Mobile IP home agent discovery

ABSTRACT

Systems and methodologies are described that facilitate Mobile IP home agent (HA) discovery in a wireless communication system. Discovery of a HA for Mobile IP can be conducted as described herein for a mobile terminal located on a network wherein movement of the terminal is managed by a network-based mobility protocol. For example, various aspects described herein can be utilized for discovery of a HA located in a 3GPP network from 3GPP and/or non-3GPP access. Further, various aspects described herein can be utilized to discover a gateway acting as mobility anchor for a network mobility protocol utilized by the network. As additionally described herein, HA discovery can be conducted in connection with DNS query formation and communication, network attach and/or re-attach procedures, Neighbor Discovery signaling, and/or other procedures.

CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application Ser.No. 60/943,017, filed Jun. 8, 2007, and entitled “MOBILE IP HOME AGENTDISCOVERY,” the entirety of which is incorporated herein by reference.

BACKGROUND

I. Field

The present disclosure relates generally to wireless communications, andmore specifically to techniques for establishing Mobile InternetProtocol (Mobile IP) communication in a wireless communication system.

II. Background

Wireless communication systems are widely deployed to provide variouscommunication services; for instance, voice, video, packet data,broadcast, and messaging services can be provided via such wirelesscommunication systems. These systems can be multiple-access systems thatare capable of supporting communication for multiple terminals bysharing available system resources. Examples of such multiple-accesssystems include Code Division Multiple Access (CDMA) systems, TimeDivision Multiple Access (TDMA) systems, Frequency Division MultipleAccess (FDMA) systems, and Orthogonal Frequency Division Multiple Access(OFDMA) systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals. Insuch a system, each terminal can communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link can be established via a single-in-single-out (SISO),multiple-in-signal-out (MISO), or a multiple-in-multiple-out (MIMO)system.

Mobile Internet Protocol (Mobile IP or MIP) is a communication protocolthat enables transparent routing of data packets to mobile devices in awireless communication system. Under the Mobile IP protocol, a devicecan register with a home agent (HA), through which the device obtains a“home” IP address. The home address of the device can then be utilizedto route data packets to and/or from the device regardless of thelocation of the device within a wireless communication network.Conventionally, a mobile device can register with a HA by firstdiscovering a global IP address of the HA and subsequently setting up asecurity association with the HA based on its discovered IP address.Upon association with the HA, the device can signal updates to the HArelating to the location and/or status of the device. These updates canbe utilized by the HA to provide data packets to the device, eitherdirectly or indirectly via an access point of a disparate network towhich the device has moved.

However, discovery of the IP address of a HA has proven difficult inwireless communication networks where mobility of devices is managed bya network-based mobility protocol, such as General Packet Radio Service(GPRS) Tunneling Protocol (GTP) or the like. For example, the home linkfor Mobile IP in a given network may be conducted through GPRS oranother similar technique such that a mobile device in the network doesnot need to be aware of the global address of its anchor point and/or HAwhile in its home network. As a consequence of the mobile device lackingknowledge of the global address of its corresponding HA, mobility of thedevice is made more complex and difficult. Accordingly, there exists aneed for versatile techniques for Mobile IP HA discovery in a wirelesscommunication network.

SUMMARY

The following presents a simplified summary of various aspects of theclaimed subject matter in order to provide a basic understanding of suchaspects. This summary is not an extensive overview of all contemplatedaspects, and is intended to neither identify key or critical elementsnor delineate the scope of such aspects. Its sole purpose is to presentsome concepts of the disclosed aspects in a simplified form as a preludeto the more detailed description that is presented later.

According to an aspect, a method for identifying a Mobile InternetProtocol (MIP) home agent (HA) in a wireless communication system isdescribed herein. The method can comprise identifying a Packet DataNetwork Gateway (PDN GW) serving as an anchor point of a network-basedmobility protocol used for communication in the wireless communicationsystem; communicating one or more messages to the identified PDN GWcontaining respective requests for a MIP HA address; and receivinginformation relating to the MIP HA address from the PDN GW in responseto the one or more messages.

Another aspect relates to a wireless communications apparatus, which cancomprise a memory that stores data relating to a HA for Mobile IPcommunication and an access router (AR) that manages the wirelesscommunications apparatus using at least one of Proxy Mobile IP (PMIP) orGeneral Packet Radio Service Tunneling Protocol (GTP). The wirelesscommunications apparatus can further comprise a processor configured toprovide one or more messages to the AR requesting a global address forthe HA and to receive information corresponding to the global address ofthe HA in response.

Yet another aspect relates to an apparatus that facilitates discovery ofa Mobile IP home agent. The apparatus can comprise means forcommunicating a request for a global IP address of a home agent to a PDNGW serving as an anchor point of a network-based mobility protocol; andmeans for receiving information relating to the global IP address of thehome agent in response to the request.

Still another aspect relates to a machine-readable medium having storedthereon instructions which, when executed by a machine, cause themachine to perform operations comprising identifying a serving accessrouter serving as a network anchor point for one or more of PMIP or GTP;determining whether a MIP HA is collocated with the serving accessrouter; if a MIP HA is collocated with the serving access router,discovering a global address for the MIP HA; and if a MIP HA is notcollocated with the serving access router, establishing a connectionwith an access router at which a MIP HA is located and discovering aglobal address for the MIP HA upon establishment of a connection withthe access router.

An additional aspect relates to an integrated circuit that executescomputer-executable instructions for discovering a global address of ahome agent. The instruction can comprise requesting a global address ofa home agent from a PDN GW serving as an anchor point for at least oneof PMIP or GTP by employing at least one of a Domain Name Service (DNS)query for a domain name configured based on the home agent or aconnection attachment procedure; and receiving information relating tothe global address of the home agent from the PDN GW.

According to another aspect, a method for coordinating discovery of aMIP HA is described herein. The method can comprise identifying a mobileterminal managed through one or more of PMIP or GTP; receiving one ormore messages from the identified mobile terminal containing respectiverequests for a global MIP HA address; and transmitting informationrelating to the global MIP HA address in response to the one or moremessages.

A further aspect relates to a wireless communications apparatus that cancomprise a memory that stores data relating to an access terminal forwhich the wireless communications apparatus serves as a PDN GW and ananchor point for a network-based mobility protocol and one or morecommunications of data received from the access terminal. The wirelesscommunications apparatus can further comprise a processor configured toidentify respective requests for a global home agent address from thecommunications of data received from the access terminal and tocommunicate an indication of the global home agent address to the accessterminal in response to the requests.

Another aspect relates to an apparatus that facilitates MIP HAdiscovery. The apparatus can comprise means for receiving a request froma user equipment (UE) managed via one or more of PMIP or GTP for aglobal address corresponding to a MIP HA address for the UE; and meansfor transmitting information corresponding to the global address of theMIP HA to the UE in response to the request.

Yet another aspect relates to a machine-readable medium having storedthereon instructions which, when executed by a machine, cause themachine to perform operations comprising identifying informationcomprising one or more of a DNS query, a Router Solicitation message, oran attachment request provided by a terminal managed via at least one ofPMIP or GTP; and providing information to the terminal relating to aglobal address of a home agent for the terminal in response to theidentified information.

Still another aspect relates to an integrated circuit that executescomputer-executable instructions for facilitating discovery of a homeagent at a requesting mobile device. The instructions can compriseidentifying a mobile device utilizing at least one of PMIP or GTP formobility management through an associated wireless communicationnetwork; receiving a request for a global home agent address from themobile device in connection with at least one of a DNS query for adomain name configured based on the home agent or a connectionattachment procedure; and relaying information relating to the globalhome agent address to the mobile device.

To the accomplishment of the foregoing and related ends, one or moreaspects of the claimed subject matter comprise the features hereinafterfully described and particularly pointed out in the claims. Thefollowing description and the annexed drawings set forth in detailcertain illustrative aspects of the claimed subject matter. Theseaspects are indicative, however, of but a few of the various ways inwhich the principles of the claimed subject matter can be employed.Further, the disclosed aspects are intended to include all such aspectsand their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless multiple-access communication system inaccordance with various aspects set forth herein.

FIG. 2 illustrates mobility of a terminal through a wirelesscommunication system in accordance with various aspects.

FIGS. 3-6 are block diagrams of respective systems for Mobile IP homeagent discovery in a wireless communication network.

FIGS. 7-10 are flow diagrams of respective methodologies for identifyinga Mobile IP home agent in a wireless communication network.

FIGS. 11-14 are flow diagrams of facilitating discovery of a home agentat a mobile terminal.

FIG. 15 is a block diagram illustrating an example wirelesscommunication system in which various aspects described herein canfunction.

FIG. 16 is a block diagram of a system that coordinates discovery of ahome agent in accordance with various aspects.

FIG. 17 is a block diagram of a system that provides informationrelating to a home agent to one or more terminals in accordance withvarious aspects.

FIGS. 18-19 are block diagrams of respective apparatus that facilitateMobile IP home agent discovery in a wireless communication system.

DETAILED DESCRIPTION

Various aspects of the claimed subject matter are now described withreference to the drawings, wherein like reference numerals are used torefer to like elements throughout. In the following description, forpurposes of explanation, numerous specific details are set forth inorder to provide a thorough understanding of one or more aspects. It maybe evident, however, that such aspect(s) may be practiced without thesespecific details. In other instances, well-known structures and devicesare shown in block diagram form in order to facilitate describing one ormore aspects.

As used in this application, the terms “component,” “module,” “system,”and the like are intended to refer to a computer-related entity, eitherhardware, firmware, a combination of hardware and software, software, orsoftware in execution. For example, a component can be, but is notlimited to being, a process running on a processor, an integratedcircuit, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a computing device and the computing device can be a component. Oneor more components can reside within a process and/or thread ofexecution and a component can be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components can communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets (e.g., data from one component interacting withanother component in a local system, distributed system, and/or across anetwork such as the Internet with other systems by way of the signal).

Furthermore, various aspects are described herein in connection with awireless terminal and/or a base station. A wireless terminal can referto a device providing voice and/or data connectivity to a user. Awireless terminal can be connected to a computing device such as alaptop computer or desktop computer, or it can be a self containeddevice such as a personal digital assistant (PDA). A wireless terminalcan also be called a system, a subscriber unit, a subscriber station,mobile station, mobile, remote station, access point, remote terminal,access terminal, user terminal, user agent, user device, or userequipment. A wireless terminal can be a subscriber station, wirelessdevice, cellular telephone, PCS telephone, cordless telephone, a SessionInitiation Protocol (SIP) phone, a wireless local loop (WLL) station, apersonal digital assistant (PDA), a handheld device having wirelessconnection capability, or other processing device connected to awireless modem. A base station (e.g., access point) can refer to adevice in an access network that communicates over the air-interface,through one or more sectors, with wireless terminals. The base stationcan act as a router between the wireless terminal and the rest of theaccess network, which can include an Internet Protocol (IP) network, byconverting received air-interface frames to IP packets. The base stationalso coordinates management of attributes for the air interface.

Moreover, various aspects or features described herein can beimplemented as a method, apparatus, or article of manufacture usingstandard programming and/or engineering techniques. The term “article ofmanufacture” as used herein is intended to encompass a computer programaccessible from any computer-readable device, carrier, or media. Forexample, computer readable media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips. . . ), optical disks (e.g., compact disk (CD), digital versatile disk(DVD) . . . ), smart cards, and flash memory devices (e.g., card, stick,key drive . . . ).

Various techniques described herein can be used for various wirelesscommunication systems, such as Code Division Multiple Access (CDMA)systems, Time Division Multiple Access (TDMA) systems, FrequencyDivision Multiple Access (FDMA) systems, Orthogonal Frequency DivisionMultiple Access (OFDMA) systems, Single Carrier FDMA (SC-FDMA) systems,and other such systems. The terms “system” and “network” are often usedherein interchangeably. A CDMA system can implement a radio technologysuch as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRAincludes Wideband-CDMA (W-CDMA) and other variants of CDMA.Additionally, CDMA2000 covers the IS-2000, IS-95 and IS-856 standards. ATDMA system can implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system can implement a radiotechnology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release of UMTSthat uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on theuplink. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents froman organization named “3rd Generation Partnership Project” (3GPP).Further, CDMA2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2).

Various aspects will be presented in terms of systems that can include anumber of devices, components, modules, and the like. It is to beunderstood and appreciated that the various systems can includeadditional devices, components, modules, etc. and/or can not include allof the devices, components, modules etc. discussed in connection withthe figures. A combination of these approaches can also be used.

Referring now to the drawings, FIG. 1 is an illustration of a wirelessmultiple-access communication system in accordance with various aspects.In one example, an access point 100 (AP) includes multiple antennagroups. As illustrated in FIG. 1, one antenna group can include antennas104 and 106, another can include antennas 108 and 110, and another caninclude antennas 112 and 114. While only two antennas are shown in FIG.1 for each antenna group, it should be appreciated that more or fewerantennas may be utilized for each antenna group. In another example, anaccess terminal 116 (AT) can be in communication with antennas 112 and114, where antennas 112 and 114 transmit information to access terminal116 over forward link 120 and receive information from access terminal116 over reverse link 118. Additionally and/or alternatively, accessterminal 122 can be in communication with antennas 106 and 108, whereantennas 106 and 108 transmit information to access terminal 122 overforward link 126 and receive information from access terminal 122 overreverse link 124. In a frequency division duplex (FDD) system,communication links 118, 120, 124 and 126 can use different frequencyfor communication. For example, forward link 120 may use a differentfrequency then that used by reverse link 118.

Each group of antennas and/or the area in which they are designed tocommunicate can be referred to as a sector of the access point. Inaccordance with one aspect, antenna groups can be designed tocommunicate to access terminals in a sector of areas covered by accesspoint 100. In communication over forward links 120 and 126, thetransmitting antennas of access point 100 can utilize beamforming inorder to improve the signal-to-noise ratio of forward links for thedifferent access terminals 116 and 122. Also, an access point usingbeamforming to transmit to access terminals scattered randomly throughits coverage causes less interference to access terminals in neighboringcells than an access point transmitting through a single antenna to allits access terminals.

An access point, e.g., access point 100, can be a fixed station used forcommunicating with terminals and can also be referred to as a basestation, a Node B, an access network, and/or other suitable terminology.In addition, an access terminal, e.g., an access terminal 116 or 122,can also be referred to as a mobile terminal, user equipment (UE), awireless communication device, a terminal, a wireless terminal, and/orother appropriate terminology.

FIG. 2 illustrates mobility of a terminal 220 through a wirelesscommunication system in accordance with various aspects. In one example,a first access point 210 and a mobile terminal 220 can initiallycommunicate via a cellular communication network 232 as shown in diagram202. As diagram 202 illustrates, access point 210 can be and/or includethe functionality of a home agent (HA) 212 for Mobile Internet Protocol(Mobile IP or MIP) and/or an access router (AR) 214, which can serve asthe anchor point for mobile terminal 220 pursuant to a network-basedmobility protocol such as Proxy Mobile IP (PMIP), General Packet RadioService (GPRS) Tunneling Protocol (GTP) or the like.

In accordance with one aspect, Mobile IP communication functionality canbe provided by HA 212 to allow communication of data packets and/orother information to mobile terminal 220 using IP-layer signalingregardless of a present location of mobile terminal 220. In one example,mobile terminal 220 can register with HA 212, thereby obtaining a “home”IP address with HA 212. By doing so, mobile terminal 220 can communicateusing IP based on the home address of the mobile terminal 220 regardlessof movement of the mobile terminal 220 within network 232 and/or other,disparate networks. In one example, HA 212 can maintain a table of homeIP addresses assigned to various terminals and utilize the table toidentify an incoming data packet for a specified terminal based on ahome address of the terminal.

In accordance with another aspect, in the event that mobile terminal 220moves outside the coverage of a network served by HA 212, Mobile IPcommunication can be conducted as illustrated by diagram 204. As diagram204 illustrates, the mobile terminal 220 can register with a secondaccess point 240 that serves a network to which mobile terminal 220moves. In one example, access point 240 and mobile terminal 220 cancommunicate through a cellular communication network 234, which canutilize the same protocol(s) for communication as network 232 and/ordifferent protocol(s). Additionally, in a similar manner to access point210, access point 240 can be and/or include the functionality of aforeign agent (FA) 242 for Mobile IP and/or an AR 244 that serves as ananchor point for a network-based mobility protocol associated withnetwork 234.

In one example, mobile terminal 220 can register with or otherwiseassociate with FA 242 to establish a “care-of” address that is utilizedwhile the mobile terminal 220 remains within the coverage of the networkserved by access point 240. The established care-of address can then beforwarded back to HA 212 in order to facilitate continued communicationwith mobile terminal 220 using the home address of the mobile terminal220 as known to HA 212. In another example, information relating to HA212 can be provided to FA 242 by mobile terminal 220 during and/or afterregistration with FA 242.

In accordance with one aspect, HA 212 and FA 242 can interact to provideMobile IP connectivity for a mobile terminal 220 as illustrated indiagram 204. More particularly, a communicating node 250 desiring totransmit information to and/or receive information from mobile terminal220 can initiate communication with mobile terminal 220 using the homeaddress of the mobile terminal 220. Upon initiating communication, HA212 can look up the present location of mobile terminal 220. If mobileterminal 220 is presently located within the network associated with HA212, data can be forwarded between the communicating node 250 and mobileterminal 220 through the network. Alternatively, as illustrated bydiagram 204, mobile terminal 220 is located outside the networkassociated with HA 212, HA 212 can initiate data tunneling to provideinformation to and/or from an appropriate FA 242 based on the care-ofaddress of mobile terminal 220 provided by mobile terminal 220 and/or FA242.

As described herein, Mobile IP techniques, such as Mobile IPv4 andMobile IPv6, provide mobility support based on signaling messagesprovided by mobile terminal 220 to HA 212. In accordance with oneaspect, in order for mobile terminal 220 to communicate appropriatesignaling messages to HA 212, mobile terminal 220 is first required todiscover the IP address of HA 212 and set up a security association withHA 212 based on the discovered IP address thereof.

However, discovery of the global IP address of HA 212 becomes difficultwhen Mobile IP is applied to a 3GPP core network or, more generally, anynetwork wherein movements of mobile terminals 220 are managed through anetwork-based protocol. More particularly, operators of wirelesscommunication networks can impose requirements for HA assignment anddiscovery that are not met by existing HA discovery techniques. Forexample, 3GPP networks utilize Access Point Name (APN) for respectivewireless access points, which can be utilized by a mobile terminal toindicate a network to which the terminal desires to attach. The conceptof APN, however, is not considered in existing HA discovery techniques.Further, existing HA discovery techniques generally do not take intoaccount that a particular mobile terminal can attach to a given networkbased on any type of access, whether 3GPP or non-3GPP, and that HAdiscovery should therefore not be based on access-specific capabilitiesor information.

As an additional example, existing HA discovery techniques do notconsider the scenario wherein 3GPP access is considered the home linkfor Mobile IP for a given terminal, which can be required by a networkoperator if it is desired to avoid Mobile IP tunneling in connectionwith 3GPP access. Such a scenario can additionally and/or alternativelyarise in the event that an APN used for discovery of a 3GPP AR (e.g., aGateway GPRS Support Node or GGSN) is the same as an APN used for HAdiscovery, such as when a HA and AR are collocated. Because movements ofa mobile terminal in a 3GPP core network in such a scenario are managedthrough a network-based protocol (e.g., PMIP or GTP), a mobile terminaldoes not need to be aware of the gateway that is acting as the anchorpoint for its location changes while in the 3GPP network. However, ifthe mobile terminal moves to an access network where network-basedmobility is not supported and/or another network where it is desirableto utilize Mobile IP to manage movements, the terminal must thendiscover the address of the HA that is collocated with the anchor pointof the network-based mobility protocol used in the 3GPP network. As aresult, a mechanism to match allocation of an anchor point for anetwork-based mobility protocol and a subsequent Mobile IP HA discoveredby a terminal is required in such a scenario.

In view of the above shortcomings of existing HA discovery techniques,various aspects described herein can be utilized to facilitate discoveryof a HA for Mobile IP at a mobile terminal located on a network whereinmovement of the terminal is managed by a network-based mobilityprotocol. For example, various aspects described herein can be utilizedby a mobile terminal to discover a HA located in a 3GPP network from anyaccess, either 3GPP or non-3GPP. Further, various aspects describedherein can be utilized to discover the same gateway that was acting asmobility anchor for a network mobility protocol utilized by the network.In accordance with one aspect, HA discovery can be achieved by a mobileterminal at least in part by identifying an anchor point of anetwork-based mobility protocol associated with a network in which theterminal is located, communicating one or more messages to theidentified anchor point containing respective requests for a Mobile IPHA address, and receiving information relating to the Mobile IP HAaddress in response to the messages. Further, techniques for HAdiscovery as described herein can be used in connection with DNS queryformation and communication, network attach and/or re-attach procedures,Neighbor Discovery signaling, and/or other appropriate procedures.Example HA discovery techniques that can be performed in accordance withvarious aspects are described in further detail infra.

FIG. 3 is a block diagram that illustrates an example system 300 forMobile IP home agent discovery in accordance with various aspects. Inone example, system 300 includes an AR 310, which can serve as theanchor point of a network-based mobility protocol for one or more accessterminals (ATs) 320. As system 300 illustrates, AR 310 can be and/orotherwise incorporate the functionality of a Mobile IP HA 312 for accessterminal 320. It should be appreciated, however, that while system 300illustrates HA 312 as collocated with AR 310, AR 310 and HA 312 couldalternatively be implemented as separate entities in system 300.

In accordance with one aspect, AR 310 can act as a DNS server for one ormore DNS queries provided by an AT 320. For example, AT 320 can utilizea processor 322 and/or memory 324 to configure a fully qualified domainname (FQDN) 326 based on a Mobile IP HA 312 for which discovery isdesired and to communicate a DNS query based on the configured FQDN 326.In one example, FQDN 326 can be configured by AT 320 based on an AccessPoint Name (APN) of AR 310 and/or HA 312. Additionally and/oralternatively, FQDN 326 can be configured based on the identity(ies) ofAT 320 and/or any other appropriate entities in system 300 as well as anoperator of system 300. By way of example, for a terminal with identityA operating in a system operated by Operator X, a configured FQDN 326can be homeagent.servingA.OperatorX.com. or the like.

Upon communication of a DNS query by AT 320, AR 310 can intercept theDNS query in order to process it. By way of example, if network trafficfrom AT 320 is routed through AR 310, AR 310 can examine trafficreceived from AT 320 to identify DNS queries received therefrom.Additionally and/or alternatively, AR 310 can be configured to act as aDNS server for AT 320 such that all DNS queries from AT 320 are directedto and/or processed by AR 310. In accordance with one aspect, AR 310 canbe configured with DNS entries corresponding to FQDNs for which itselfor another AR associated therewith can act as HA for a requesting AT.Accordingly, if a DNS query received by AR 310 contains a FQDN for whicha corresponding DNS entry at AR 310 exists, AR 310 can reply to the DNSquery with an appropriate HA address, thereby acting as theauthoritative name server for said FQDN. For example, if a DNS query isreceived from AT 320 for a FQDN 326 corresponding to a HA 312 collocatedwith AR 310, AR 310 can reply to the DNS query with its own IP address.Alternatively, if AR 310 receives a DNS query from AT 320 for a FQDN 326corresponding to another AR that can serve as HA for AT 320, AR 310 canreply to the DNS query with an IP address of the AR corresponding to theFQDN 326.

In accordance with one aspect, the role of AR 310 can vary based oncommunication protocol(s) utilized by system 300. For example, AR 310can be a Packet Data Network Gateway (PDN GW) in 3GPP SystemArchitecture Evolution (SAE), a GGSN in UMTS and/or GPRS, a Packet DataGateway (PDG) in an Interworked Wireless Local Area Network (I-WLAN),and/or any other suitable network entity.

FIG. 4 is a block diagram that illustrates another example system 400for Mobile IP home agent discovery in accordance with various aspects.In one example, system 400 includes an AR 410, which can serve as theanchor point of a network-based mobility protocol for one or more ATs420. Further, AR 410 can be configured to be the default gateway of AT420. Accordingly, a Mobile IP HA 412 can be collocated with AR 410 suchthat AT 420 is configured to select AR 410 as its HA 412.

In accordance with one aspect, if a network-based mobility protocol(e.g., GTP or another suitable protocol) is utilized to manage ATs 420in system 400, an AT 420 generally is not provided with knowledge of theIP address of an AR 410 that serves as its default gateway. Accordingly,in order to discover the IP address of HA 412, AT 420 can utilize one ormore procedures for identifying the IP address of an AR 410 serving asits default gateway at which a HA 412 is collocated. In one example, HAdiscovery can be carried out by AT 420 through Neighbor Discoverysignaling. For example, as system 400 illustrates, AT 420 cancommunicate a Router Solicitation message to AR 410. In return, AR 410,acting as HA 412 for AT 420, can reply to the Router Solicitationmessage with a Router Advertisement message that includes the global IPaddress of AR 410. In a system where a HA 412 is collocated with AR 410,AT can then utilize the IP address of AR 410 obtained through the RouterAdvertisement message as its HA address.

FIG. 5 is a block diagram that illustrates an additional example system400 for Mobile IP home agent discovery in accordance with variousaspects. In one example, system 500 includes an AR 510, which can serveas the anchor point of a network-based mobility protocol for one or moreATs 520. In accordance with one aspect, AR 510 and AT 520 cancommunicate within system 500 based on 3GPP access. For example, assystem 500 illustrates, AR 510 and AT 520 can utilize a LTE attachprocedure to establish a communication link therebetween. By way ofexample, an LTE attach procedure can be initiated by AT 520 bycommunicating an attach request message to AR 510. In response to anattach request message, AR 510 can provide an attach accept message toAT 520. In accordance with one aspect, an attach accept message providedto AT 520 by AR 510 can include the IP address of a HA 512 for the AT520. The IP address of HA 512 can be can be provided in any suitableportion of the attach accept message, such as in a protocolconfiguration option carried by the attach accept message and/or in anyother portion of the attach accept message. Alternatively, the IPaddress of HA 512 can be provided by AR 510 or a Mobility ManagementEntity (MME) in a message that is disparate from the attach acceptmessage. Additionally, it should be appreciated that while system 500illustrates an example HA 512 collocated with AR 510, HA 512 canalternatively be a stand-alone entity or collocated with another networkentity.

FIG. 6 is a block diagram that illustrates a further system 600 forMobile IP HA discovery in accordance with various aspects. In oneexample, HA discovery can begin as illustrated in diagram 602 between anAT 620 and a first AR 610 that is assigned to the AT 620 as the anchorpoint of a network-based mobility protocol. As diagram 602 furtherillustrates, AT 620 can conduct DNS-based HA discovery by submitting aDNS query to AR 610. In one example, the DNS query submitted by AT 620can be based on an APN and/or FQDN for a HA to be discovered, which canbe configured in a substantially similar manner to that described suprawith respect to system 300. Additionally and/or alternatively, a DNSquery provided by AT 620 can be received and/or processed by AR 610 in asimilar manner to that described supra with respect to AR 310.

In accordance with one aspect, AR 610 can provide a DNS reply to AT 620that indicates the global address of a HA for the AT. In one example,the DNS reply can provide the global IP address of the HA, either byincluding the global IP address of AR 610 if the HA is collocated withAR 610 or by providing the global IP address of another AR or othernetwork entity at which the HA is collocated. Alternatively, AR 610 canadditionally provide a link-local address for an entity with which theHA is collocated if the HA is not collocated with AR 610.

In accordance with another aspect, if a DNS reply received from AR 610indicates that a HA for AT 620 is located at a different network nodethan AR 610, AT 620 can subsequently associate with the HA asillustrated in diagram 604. For example, as diagram 604 illustrates, aHA 632 designated for AT 620 is collocated with a second AR 630 that isdisparate from the first AR 610. Accordingly, to associate with HA 632,AT 620 can de-attach from AR 610 by exchanging de-attach signaling withAR 610 as illustrated by diagram 604. Subsequently, AT 620 can re-attachto AR 630 and HA 632 by exchanging re-attach signaling with AR 630. Inaccordance with one aspect, re-attach messages can be communicatedbetween AR 630 and AT 620 pursuant to a LTE re-attach procedure and/oranother appropriate procedure.

In one example, the global IP address of HA 632 can be provided to AT620 prior to re-attachment with AR 630. Alternatively, the global IPaddress of HA 632 can be provided to AT 620 upon re-attachment with AR630. For example, the address of HA 632 can be stored on anAuthentication Authorization Accounting Home Subscriber Server (AAA/HSS)associated with AR 630, retrieved during the re-attach procedure betweenAR 630 and AT 620, and assigned to AT 620 following re-attachment. Inaccordance with one aspect, an assignment of HA 632 to AT 620 can bemade in a re-attach accept message communicated to AT 620 and/or in aseparate message, such as a DNS message provided to AT 620 usingIP-layer signaling and/or another suitable network-dependent ornetwork-independent technique.

Referring to FIGS. 7-14, methodologies that can be performed inaccordance with various aspects set forth herein are illustrated. While,for purposes of simplicity of explanation, the methodologies are shownand described as a series of acts, it is to be understood andappreciated that the methodologies are not limited by the order of acts,as some acts can, in accordance with one or more aspects, occur indifferent orders and/or concurrently with other acts from that shown anddescribed herein. For example, those skilled in the art will understandand appreciate that a methodology could alternatively be represented asa series of interrelated states or events, such as in a state diagram.Moreover, not all illustrated acts may be required to implement amethodology in accordance with one or more aspects.

With reference to FIG. 7, illustrated is a methodology 700 foridentifying a Mobile IP home agent in a wireless communication system(e.g., system 200). It is to be appreciated that methodology 700 can beperformed by, for example, a mobile device (e.g., mobile terminal 220)and/or any other appropriate network entity. Methodology 700 begins atblock 702, wherein an anchor point (e.g., AR 214 and/or AP 210) of anetwork-based mobility protocol (e.g., GTP and/or PMIP) used forcommunication in a wireless communication system is identified. Ananchor point identified at block 702 can be a serving anchor point foran entity performing methodology 700, or alternatively the identifiedanchor point can be located in a network to which the entity performingmethodology 700 is connecting. Further, the anchor point identified atblock 702 can be a PDN GW and/or any other suitable network entity.

Next, at block 704, one or more messages are communicated to the anchorpoint identified at block 702 that contain respective implicit and/orexplicit requests for a Mobile IP home agent address. Messagescommunicated at block 704 can be based on, for example, DNS signaling,an LTE attachment and/or re-attachment procedure, Neighbor Discoverysignaling, and/or any other suitable type of communication. Methodology700 can then conclude at block 706, wherein information relating to theMobile IP home agent address is received from the anchor pointidentified at block 702 in response to the messages communicated atblock 704. In accordance with one aspect, information received at block706 can include the Mobile IP home agent address itself and/or otherinformation to further facilitate its discovery. For example,information received at block 706 can include a local address of asecond anchor point at which a home agent is collocated in order tofacilitate a subsequent connection to the second anchor point.

FIG. 8 illustrates a methodology 800 for identifying a Mobile IP homeagent based on DNS signaling. Methodology 800 can be performed by amobile terminal and/or any other suitable network entity. Methodology800 begins at block 802, wherein an anchor point of a network-basedmobility protocol used for communication in a wireless communicationsystem is identified. Next, at block 804, a FQDN for a serving Mobile IPhome agent to be discovered is configured. A FQDN for the home agent canbe configured at block 804 based on an APN associated with the homeagent, an identity of the entity performing methodology 800, an identityof the anchor point identified at block 802, an operator of the wirelesscommunication system, and/or other suitable factors. At block 806, a DNSquery is then submitted to the anchor point identified at block 802 forthe FQDN identified at block 804.

Methodology 800 then proceeds to block 808, wherein a Mobile IP homeagent address is received in response to the DNS query submitted atblock 806. In accordance with one aspect, an address received at block808 can be a global address (e.g., an IP address) of the home agent or alocal address to another entity in the wireless communication systemwith which the home agent is collocated. Next at block 810, it isdetermined based on the address received at block 808 whether the homeagent is collocated with the anchor point identified at block 802. Ifthe home agent is collocated with the anchor point, then it can beinferred that the address received at block 808 is the global address ofthe home agent and methodology 800 concludes. Otherwise, methodology 800proceeds to block 812, wherein the entity performing methodology 800detaches from the anchor point identified at block 802. Detachment atblock 812 can be performed using, for example, an exchange of detachmentsignaling messages and/or other suitable means. Methodology 800 can thenconclude at block 814, wherein re-attachment to a new anchor pointassociated with the home agent corresponding to the address received atblock 808 is conducted. Re-attachment at block 808 can be performed byusing, for example, an LTE re-attach procedure involving the exchange ofre-attachment messages and/or other appropriate means. In accordancewith one aspect, a re-attach message received from the new anchor pointat block 814 can include and/or otherwise indicate a global home agentaddress. Additionally and/or alternatively, a global home agent addresscan be received from the anchor point or an associated MME in a separatemessage upon re-attachment at block 814.

FIG. 9 illustrates a methodology 900 for identifying a Mobile IP homeagent based on Neighbor Discovery signaling. It should be appreciatedthat methodology 900 can be performed by, for example, an accessterminal and/or any other appropriate network entity. Methodology 900begins at block 902, wherein an anchor point of a network-based mobilityprotocol with which a Mobile IP home agent is collocated is identified.Next, at block 904, a Router Solicitation message is communicated to theanchor point identified at block 902. Methodology 900 can then concludeat block 906, wherein a Router Advertisement message is received fromthe anchor point identified at block 902 that includes a global IPaddress of the home agent collocated therewith in response to the RouterSolicitation message communicated at block 904.

FIG. 10 is a flow diagram that illustrates a methodology 1000 foridentifying a Mobile IP home agent based on a network attachmentprocedure. Methodology 1000 can be performed by a mobile device and/orany other suitable network entity. Methodology 1000 begins at block1002, wherein an anchor point of a network-based mobility protocol towhich communication is to be established is identified. Methodology 1000can then proceed to block 1004, wherein an attach request message iscommunicated to the anchor point identified at block 1002. Methodology1000 can then conclude at block 1006, wherein an attach accept messageand/or a global IP address of a home agent are received from the anchorpoint identified at block 1002 in response to the attach request messagecommunicated to the anchor point at block 1004. In accordance with oneaspect, the global IP address received at block 1006 can be receivedfrom the anchor point identified at 1002 and/or a MME associated withthe anchor point. In addition, the global IP address can be received aspart of the attach accept message (e.g., in a protocol configurationoption carried by the attach accept message) or separately from theattach accept message.

With reference to FIG. 11, illustrated is a methodology 1100 forfacilitating discovery of a home agent at a mobile terminal (e.g., an AT220 in system 200). It is to be appreciated that methodology 1100 can beperformed by, for example, a wireless access point and/or access router(e.g., AP 210 and/or AR 214) and/or any other appropriate networkentity. By way of further specific, non-limiting example, an entityperforming methodology 1100 can serve as a PDN GW for one or more mobileterminals. Methodology 1100 begins at block 1102, wherein a mobileterminal managed through a network-based mobility protocol (e.g., PMIPand/or GTP) is identified. In accordance with one aspect, a terminalidentified at block 1102 can be a terminal for which a communicationlink has previously been established or a terminal for which acommunication link is to be established. For example, a terminal can beidentified at block 1102 by receiving a request from the terminal forestablishment of a communication link.

Next, at block 1104, one or more messages are received from the mobileterminal identified at block 1102 that contain respective implicitand/or explicit requests for a global home agent address. Messagesreceived at block 1104 can be based on, for example, DNS signaling, anLTE attachment and/or re-attachment procedure, Neighbor Discoverysignaling, and/or any other suitable type of communication. Methodology1100 can then proceed to block 1106, wherein information relating to thehome agent address is transmitted to the mobile terminal identified atblock 1102 in response to the message(s) received at block 1104. Inaccordance with one aspect, information transmitted at block 1106 caninclude the home agent address itself and/or other information relatingto an entity at which the home agent is collocated. For example,information received at block 1106 can include a local address of ananchor point at which the home agent is collocated to facilitate asubsequent connection between the terminal identified at block 1102 andthe anchor point.

FIG. 12 illustrates a methodology 1200 for facilitating discovery of ahome agent based on DNS signaling. Methodology 1200 can be performed by,for example, a wireless access point, an access router, and/or any otherappropriate network entity. Methodology 1200 begins at block 1202,wherein a terminal managed through a network-based mobility protocol isidentified. Next, at block 1204, a DNS query communicated from theterminal identified at block 1202 that is based on a domain name thatindicates a home agent for the terminal is identified. The domain nameon which the DNS query identified at block 1204 is based can beconfigured based on an APN associated with the home agent, an identityof the terminal identified at block 1202, an operator of the wirelesscommunication system, and/or other suitable factors. Further, the DNSquery can be identified at block 1204 by intercepting some or all DNSqueries from the terminal identified at block 1202 and determiningwhether respective DNS queries relate to a domain name configured for ahome agent. Methodology 1200 can then conclude at block 1206, wherein aglobal IP address of the home agent is transmitted to the terminalidentified at block 1202 in response to the DNS query identified atblock 1204.

FIG. 13 relates to a methodology 1300 for facilitating discovery of ahome agent based on Neighbor Discovery signaling. Methodology 1300 canbe performed by, for example, a wireless access point, an access router,and/or any other appropriate network entity. Methodology 1300 begins atblock 1302, wherein a terminal managed through a network-based mobilityprotocol is identified. Next, at block 1304, a Router Solicitationmessage is received from the terminal identified at block 1302.Methodology 1300 can then continue to block 1306, wherein a RouterAdvertisement message is transmitted to the terminal identified at block1302 that indicates a global IP address associated with a Mobile IP homeagent for the terminal.

FIG. 14 illustrates a methodology 1400 for facilitating discovery of ahome agent based on an attachment and/or re-attachment procedure.Methodology 1400 can be performed by, for example, a wireless accesspoint, an access router, and/or any other appropriate network entity.Methodology 1400 begins at block 1402, wherein a request for attachmentor re-attachment is received from a terminal managed through anetwork-based mobility protocol. Methodology 1400 can then proceed toblock 1404, wherein a message is communicated to the terminal acceptingthe request received at block 1402 that indicates a global IP addressassociated with a Mobile IP home agent for the terminal. In a specific,non-limiting example, the message communicated at block 1404 can be anattach accept message, and the global IP address associated with theMobile IP home agent for the terminal can be provided in a protocolconfiguration option in the attach accept message.

Referring now to FIG. 15, a block diagram illustrating an examplewireless communication system 1500 in which one or more embodimentsdescribed herein can function is provided. In one example, system 1500is a multiple-input multiple-output (MIMO) system that includes atransmitter system 1510 and a receiver system 1550. It should beappreciated, however, that transmitter system 1510 and/or receiversystem 1550 could also be applied to a multi-input single-output systemwherein, for example, multiple transmit antennas (e.g., on a basestation), can transmit one or more symbol streams to a single antennadevice (e.g., a mobile station). Additionally, it should be appreciatedthat aspects of transmitter system 1510 and/or receiver system 1550described herein could be utilized in connection with a single output tosingle input antenna system.

In accordance with one aspect, traffic data for a number of data streamsare provided at transmitter system 1510 from a data source 1512 to atransmit (TX) data processor 1514. In one example, each data stream canthen be transmitted via a respective transmit antenna 1524.Additionally, TX data processor 1514 can format, encode, and interleavetraffic data for each data stream based on a particular coding schemeselected for each respective data stream in order to provide coded data.In one example, the coded data for each data stream can then bemultiplexed with pilot data using OFDM techniques. The pilot data canbe, for example, a known data pattern that is processed in a knownmanner. Further, the pilot data can be used at receiver system 1550 toestimate channel response. Back at transmitter system 1510, themultiplexed pilot and coded data for each data stream can be modulated(i.e., symbol mapped) based on a particular modulation scheme (e.g.,BPSK, QSPK, M-PSK, or M-QAM) selected for each respective data stream inorder to provide modulation symbols. In one example, data rate, coding,and modulation for each data stream can be determined by instructionsperformed on and/or provided by processor 1530.

Next, modulation symbols for all data streams can be provided to a TXprocessor 1520, which can further process the modulation symbols (e.g.,for OFDM). TX MIMO processor 1520 can then provides N_(T) modulationsymbol streams to N_(T) transceivers 1522 a through 1522 t. In oneexample, each transceiver 1522 can receive and process a respectivesymbol stream to provide one or more analog signals. Each transceiver1522 can then further condition (e.g., amplify, filter, and upconvert)the analog signals to provide a modulated signal suitable fortransmission over a MIMO channel. Accordingly, N_(T) modulated signalsfrom transceivers 1522 a through 1522 t can then be transmitted fromN_(T) antennas 1524 a through 1524 t, respectively.

In accordance with another aspect, the transmitted modulated signals canbe received at receiver system 1550 by N_(R) antennas 1552 a through1552 r. The received signal from each antenna 1552 can then be providedto respective transceivers 1554. In one example, each transceiver 1554can condition (e.g., filter, amplify, and downconvert) a respectivereceived signal, digitize the conditioned signal to provide samples, andthen processes the samples to provide a corresponding “received” symbolstream. An RX MIMO/data processor 1560 can then receive and process theAIR received symbol streams from N_(R) transceivers 1554 based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. In one example, each detected symbol stream can includesymbols that are estimates of the modulation symbols transmitted for thecorresponding data stream. RX processor 1560 can then process eachsymbol stream at least in part by demodulating, deinterleaving, anddecoding each detected symbol stream to recover traffic data for acorresponding data stream. Thus, the processing by RX processor 1560 canbe complementary to that performed by TX MIMO processor 1520 and TX dataprocessor 1514 at transmitter system 1510. RX processor 1560 canadditionally provide processed symbol streams to a data sink 1564.

In accordance with one aspect, the channel response estimate generatedby RX processor 1560 can be used to perform space/time processing at thereceiver, adjust power levels, change modulation rates or schemes,and/or other appropriate actions. Additionally, RX processor 1560 canfurther estimate channel characteristics such as, for example,signal-to-noise-and-interference ratios (SNRs) of the detected symbolstreams. RX processor 1560 can then provide estimated channelcharacteristics to a processor 1570. In one example, RX processor 1560and/or processor 1570 can further derive an estimate of the “operating”SNR for the system. Processor 1570 can then provide channel stateinformation (CSI), which can comprise information regarding thecommunication link and/or the received data stream. This information caninclude, for example, the operating SNR. The CSI can then be processedby a TX data processor 1518, modulated by a modulator 1580, conditionedby transceivers 1554 a through 1554 r, and transmitted back totransmitter system 1510. In addition, a data source 1516 at receiversystem 1550 can provide additional data to be processed by TX dataprocessor 1518.

Back at transmitter system 1510, the modulated signals from receiversystem 1550 can then be received by antennas 1524, conditioned bytransceivers 1522, demodulated by a demodulator 1540, and processed by aRX data processor 1542 to recover the CSI reported by receiver system1550. In one example, the reported CSI can then be provided to processor1530 and used to determine data rates as well as coding and modulationschemes to be used for one or more data streams. The determined codingand modulation schemes can then be provided to transceivers 1522 forquantization and/or use in later transmissions to receiver system 1550.Additionally and/or alternatively, the reported CSI can be used byprocessor 1530 to generate various controls for TX data processor 1514and TX MIMO processor 1520. In another example, CSI and/or otherinformation processed by RX data processor 1542 can be provided to adata sink 1544.

In one example, processor 1530 at transmitter system 1510 and processor1570 at receiver system 1550 direct operation at their respectivesystems. Additionally, memory 1532 at transmitter system 1510 and memory1572 at receiver system 1550 can provide storage for program codes anddata used by processors 1530 and 1570, respectively. Further, atreceiver system 1550, various processing techniques can be used toprocess the N_(R) received signals to detect the N_(T) transmittedsymbol streams. These receiver processing techniques can include spatialand space-time receiver processing techniques, which can also bereferred to as equalization techniques, and/or “successivenulling/equalization and interference cancellation” receiver processingtechniques, which can also be referred to as “successive interferencecancellation” or “successive cancellation” receiver processingtechniques.

FIG. 16 is a block diagram of a system that coordinates discovery of ahome agent in accordance with various aspects described herein. In oneexample, system 1600 includes a terminal or user equipment (UE) 1602. Asillustrated, UE 1602 can receive signal(s) from one or more Node Bs 1604and transmit to the one or more Node Bs 1604 via one or more antennas1608. Additionally, UE 1602 can comprise a receiver 1610 that receivesinformation from antenna(s) 1608. In one example, receiver 1610 can beoperatively associated with a demodulator (Demod) 1612 that demodulatesreceived information. Demodulated symbols can then be analyzed by aprocessor 1614. Processor 1614 can be coupled to memory 1616, which canstore data and/or program codes related to UE 1602. Additionally, UE1602 can employ processor 1614 to perform methodologies 700, 800, 900,1000, and/or other similar and appropriate methodologies. UE 1602 canalso include a modulator 1618 that can multiplex a signal fortransmission by a transmitter 1620 through antenna(s) 1608.

FIG. 17 is a block diagram of a system that provides informationrelating to a home agent to one or more terminals in accordance withvarious aspects described herein. In one example, system 1700 includes abase station or access point 1702. As illustrated, access point 1702 canreceive signal(s) from one or more access terminals 1704 and/or anaccess gateway (not shown) via one or more receive (Rx) antennas 1706and transmit to the one or more access terminals 1004 and/or the accessgateway via one or more transmit (Tx) antennas 1708.

Additionally, access point 1702 can comprise a receiver 1710 thatreceives information from receive antenna(s) 1706. In one example, thereceiver 1710 can be operatively associated with a demodulator (Demod)1712 that demodulates received information. Demodulated symbols can thenbe analyzed by a processor 1714. Processor 1714 can be coupled to memory1716, which can store information related to code clusters, accessterminal assignments, lookup tables related thereto, unique scramblingsequences, and/or other suitable types of information. In one example,access point 1702 can employ processor 1714 to perform methodologies1100, 1200, 1300, 1400, and/or other similar and appropriatemethodologies. Access point 1702 can also include a modulator 1718 thatcan multiplex a signal for transmission by a transmitter 1720 throughtransmit antenna(s) 1708.

FIG. 18 illustrates an apparatus 1800 that facilitates Mobile IP homeagent discovery in a wireless communication system (e.g., system 200).It is to be appreciated that apparatus 1800 is represented as includingfunctional blocks, which can be functional blocks that representfunctions implemented by a processor, software, or combination thereof(e.g., firmware). Apparatus 1800 can be implemented in a UE (e.g.,mobile terminal 220) and/or any other appropriate network entity and caninclude a module 1802 for requesting a global address for a Mobile IPhome agent from an anchor point of a network-based mobility protocol anda module 1804 for receiving information relating to the global addressof the Mobile IP home agent in response to the request.

FIG. 19 illustrates another apparatus 1900 that facilitates Mobile IPhome agent discovery in a wireless communication system (e.g., system200). It is to be appreciated that apparatus 1900 is represented asincluding functional blocks, which can be functional blocks thatrepresent functions implemented by a processor, software, or combinationthereof (e.g., firmware). Apparatus 1900 can be implemented in an accesspoint (e.g., access point 210), an access router (e.g., access router214), and/or any other appropriate network entity and can include amodule 1902 for receiving a request from a UE managed via anetwork-based mobility protocol for a global address corresponding to aMobile IP home agent for the UE and a module 1904 for transmittinginformation corresponding to the global address of the mobile IP homeagent in response to the request.

It is to be understood that the aspects described herein can beimplemented by hardware, software, firmware, middleware, microcode, orany combination thereof. When the systems and/or methods are implementedin software, firmware, middleware or microcode, program code or codesegments, they can be stored in a machine-readable medium, such as astorage component. A code segment can represent a procedure, a function,a subprogram, a program, a routine, a subroutine, a module, a softwarepackage, a class, or any combination of instructions, data structures,or program statements. A code segment can be coupled to another codesegment or a hardware circuit by passing and/or receiving information,data, arguments, parameters, or memory contents. Information, arguments,parameters, data, etc. can be passed, forwarded, or transmitted usingany suitable means including memory sharing, message passing, tokenpassing, network transmission, etc.

For a software implementation, the techniques described herein can beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. The software codes can be storedin memory units and executed by processors. The memory unit can beimplemented within the processor or external to the processor, in whichcase it can be communicatively coupled to the processor via variousmeans as is known in the art.

What has been described above includes examples of one or more aspects.It is, of course, not possible to describe every conceivable combinationof components or methodologies for purposes of describing theaforementioned aspects, but one of ordinary skill in the art canrecognize that many further combinations and permutations of variousaspects are possible. Accordingly, the described aspects are intended toembrace all such alterations, modifications and variations that fallwithin the spirit and scope of the appended claims. Furthermore, to theextent that the term “includes” is used in either the detaileddescription or the claims, such term is intended to be inclusive in amanner similar to the term “comprising” as “comprising” is interpretedwhen employed as a transitional word in a claim. Furthermore, the term“or” as used in either the detailed description or the claims is meantto be a “non-exclusive or.”

What is claimed is:
 1. A method for identifying a Mobile InternetProtocol (MIP) home agent (HA) in a wireless communication system,comprising: identifying a Packet Data Network Gateway (PDN GW) servingas an anchor point of a network-based mobility protocol used forcommunication in the wireless communication system; communicating one ormore messages to the identified PDN GW containing respective requestsfor a MIP HA address; receiving information relating to the MIP HAaddress from the PDN GW in response to the one or more messages, whereinthe information relating to the MIP HA address is provided by the PDN GWwhen the HA is collocated with the PDN GW, and wherein the informationrelating to the MIP HA address comprises information provided by adifferent device when the HA is not collocated with the PDN GW; andde-attaching from the PDN GW and re-attaching to a different PDN GWassociated with the different device if the information relating to theMIP HA address indicates that the MIP HA is collocated with thedifferent device.
 2. The method of claim 1, wherein: the communicatingone or more messages comprises communicating a Domain Name System (DNS)query to the PDN GW for a fully qualified domain name (FQDN)corresponding to the MIP HA; and the receiving comprises receiving theMIP HA address in response to the DNS query.
 3. The method of claim 2,further comprising configuring the FQDN based on an access point name(APN) associated with the MIP HA.
 4. The method of claim 2, furthercomprising configuring the FQDN based on respective identities of arequesting device and a network operator.
 5. The method of claim 1,wherein: the communicating one or more messages comprises communicatinga Router Solicitation message to the PDN GW; and the receiving comprisesreceiving a Router Advertisement message from the PDN GW that indicatesa global address for the MIP HA.
 6. The method of claim 1, wherein: theidentifying comprises identifying a PDN GW with which a connection is tobe established; the communicating one or more messages comprises sendingan attach request message to the identified PDN GW; and the receivingcomprises receiving an attach accept message from the identified PDN GWand an indication of a global address for the MIP HA.
 7. The method ofclaim 6, wherein the global address for the MIP HA is received in aprotocol configuration option provided by the attach accept message. 8.The method of claim 6, wherein the global address for the MIP HA isreceived from a Mobility Management Entity (MME) that is disparate fromthe PDN GW in a separate message from the attach accept message.
 9. Themethod of claim 1, wherein the network-based mobility protocol is atleast one of General Packet Radio Service Tunneling Protocol (GTP) orProxy Mobile Internet Protocol (PMIP).
 10. A method for identifying aMobile Internet Protocol (MIP) home agent (HA) in a wirelesscommunication system, comprising: identifying a Packet Data NetworkGateway (PDN GW) serving as an anchor point of a network-based mobilityprotocol used for communication in the wireless communication system;communicating one or more messages to the identified PDN GW containingrespective requests for a MIP HA address; and receiving informationrelating to the MIP HA address from the PDN GW in response to the one ormore messages, wherein: the identifying comprises identifying a servingPDN GW; the communicating one or more messages comprises communicating aDNS query for the MIP HA to the serving PDN GW; the receiving comprisesreceiving a DNS reply from the serving PDN GW that indicates that theMIP HA is collocated with a PDN GW disparate from the serving PDN GW;and the method further comprises de-attaching from the serving PDN GWand re-attaching to the PDN GW indicated in the DNS reply.
 11. Themethod of claim 10, wherein the receiving further comprises receiving aDNS reply from the serving PDN GW that indicates a global address forthe MIP HA.
 12. The method of claim 10, wherein: the receiving furthercomprises receiving a DNS reply that indicates a name of a PDN GW withwhich the MIP HA is collocated; and the method further comprisesreceiving a global address of the MIP HA from the PDN GW indicated inthe DNS reply upon attachment thereto.
 13. A wireless communicationsapparatus, comprising: a memory that stores data relating to a homeagent (HA) for Mobile Internet Protocol (IP) communication and an accessrouter (AR) that manages the wireless communications apparatus using atleast one of Proxy Mobile IP (PMIP) or General Packet Radio ServiceTunneling Protocol (GTP); and a processor configured to provide one ormore messages to the AR requesting a global address for the HA and toreceive information corresponding to the global address of the HA inresponse, wherein the information corresponding to the global address isprovided by the AR when the HA is collocated with the AR, and whereinthe information corresponding to the global address comprisesinformation provided by a different device when the HA is not collocatedwith the AR, wherein the processor is further configured to de-attachfrom the AR and re-attach to a different AR associated with thedifferent device if the information corresponding to the global addressindicates that the HA is collocated with the different device.
 14. Thewireless communications apparatus of claim 13, wherein the memoryfurther stores data relating to a domain name associated with the HA andthe processor is further configured to communicate a Domain Name System(DNS) query to the AR for the domain name associated with the HA and toreceive a responsive DNS reply comprising a global address of the HA.15. The wireless communications apparatus of claim 14, wherein theprocessor is further configured to configure the domain name associatedwith the HA based on an access point name (APN) associated with the HA.16. The wireless communications apparatus of claim 14, wherein theprocessor is further configured to configure the domain name associatedwith the HA based on respective identities of the wirelesscommunications apparatus and an operator of the HA.
 17. The wirelesscommunications apparatus of claim 13, wherein the processor is furtherconfigured to provide a Router Solicitation message to the AR and toreceive a Router Advertisement message from the AR in response thatincludes a global address for the HA.
 18. The wireless communicationsapparatus of claim 13, wherein the memory further stores data relatingto an AR with which a communication session is to be established and theprocessor is further configured to provide an attach request message tothe AR with which the communication session is to be established and toreceive an attach accept message and an indication of a global addressof the HA in response.
 19. The wireless communications apparatus ofclaim 18, wherein the processor is further configured to identify theglobal address of the HA in a protocol configuration option provided inthe attach accept message.
 20. The wireless communications apparatus ofclaim 18, wherein the processor is further configured to receive theglobal address of the HA from a Mobility Management Entity (MME) that isdisparate from the AR in connection with receiving the attach acceptmessage.
 21. A wireless communications apparatus, comprising: a memorythat stores data relating to a home agent (HA) for Mobile InternetProtocol (IP) communication and an access router (AR) that manages thewireless communications apparatus using at least one of Proxy Mobile IP(PMIP) or General Packet Radio Service Tunneling Protocol (GTP); and aprocessor configured to provide one or more messages to the ARrequesting a global address for the HA and to receive informationcorresponding to the global address of the HA in response wherein thememory further stores data relating to a serving AR and a domain nameassociated with the HA and the processor is further configured tocommunicate a DNS query to the AR based on the domain name of the HA, toidentify a DNS reply from the AR indicating that the HA is collocatedwith a non-serving AR, and to de-attach from the serving AR andre-attach with the AR at which the HA is located in response to the DNSreply.
 22. The wireless communications apparatus of claim 21, whereinthe processor is further configured to identify a global address for theHA in the DNS reply.
 23. The wireless communications apparatus of claim21, wherein the processor is further configured to identify a globaladdress for the HA from the AR indicated in the DNS reply duringattachment thereto.
 24. An apparatus that facilitates discovery of aMobile Internet Protocol (IP) home agent, the apparatus comprising:means for communicating a request for a global IP address of a homeagent to a Packet Data Network Gateway (PDN GW) serving as an anchorpoint of a network-based mobility protocol; means for receivinginformation relating to the global IP address of the home agent inresponse to the request, wherein the information relating to the globalIP address is provided by the PDN GW when the home agent is collocatedwith the PDN GW, and wherein the information relating to the global IPaddress comprises information provided by a different device when thehome agent is not collocated with the PDN GW; and means for de-attachingfrom the PDN GW and re-attaching to a different PDN GW associated withthe different device if the information relating to the global IPaddress indicates that the home agent is collocated with the differentdevice.
 25. A non-transitory machine-readable medium having storedthereon instructions which, when executed by a machine, cause themachine to perform operations comprising: identifying a serving accessrouter serving as a network anchor point for one or more of Proxy MobileInternet Protocol (PMIP) or General Packet Radio Service TunnelingProtocol (GTP); determining whether a first Mobile Internet Protocol(MIP) home agent (HA) is collocated with the serving access router; ifthe first MIP HA is collocated with the serving access router,discovering a global address for the first MIP HA; and if the first MIPHA is not collocated with the serving access router, establishing aconnection with an access router at which a second MIP HA is located anddiscovering a global address for the second MIP HA upon establishment ofa connection with the access router.
 26. An integrated circuit thatexecutes computer-executable instructions for discovering a globaladdress of a home agent, the instructions comprising: requesting aglobal address of a home agent from a Packet Data Network Gateway (PDNGW) serving as an anchor point for at least one of Proxy Mobile InternetProtocol (PMIP) or General Packet Radio Service Tunneling Protocol (GTP)by employing at least one of a Domain Name Service (DNS) query for adomain name configured based on the home agent or a connectionattachment procedure; receiving information relating to the globaladdress of the home agent from the PDN GW, wherein the informationrelating to the global address is provided by the PDN GW when the homeagent is collocated with the PDN GW, and wherein the informationrelating to the global address comprises information provided by adifferent device when the home agent is not collocated with the PDN GW,the different device being collocated with the home agent; andde-attaching from the PDN GW and re-attaching to a different PDN GWassociated with the different device if the information relating to theglobal address indicates that the home agent is collocated with thedifferent device.